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PDF Files for PrintingLesson 6-Environmental Hazards 

At a Glance


Students use the knowledge they have gained from previous lessons to solve a problem depicted in a fictional scenario. In the scenario, students participate in a field trip to a natural history museum. Upon returning to the school, many participants complain of headache and nausea. Students consider the potential chemical exposures experienced by the field-trip participants and analyze who was exposed, how they were exposed, and how much exposure they experienced. Using fact sheets to learn about the specific hazards and health reactions attributable to certain chemicals, students solve the problem and recommend ways that the participants could have minimized or eliminated their exposure.

Major Concepts

People can use their understanding of the science of toxicology to identify potential sources of harm to human health from chemicals in the environment. They can use their knowledge to propose possible means to eliminate or reduce exposure to environmental toxic agents.


After completing this lesson, students will

Background Information

Protecting Human Health

Decisions about chemical exposures occur at different levels. For example, a person can choose whether he or she wants to consume caffeine. In other cases, an individual is not able to control a chemical exposure simply by making a personal decision. For example, while a person might choose not to smoke in order to avoid exposure to the chemicals in tobacco smoke, he or she sometimes is unable to avoid secondhand smoke.

Sometimes there are larger social, economic, and political forces involved in hazardous exposure at a community level. As a result, organizations and agencies, including different levels of government, often become involved in prevention of chemical exposure and intervention when people suspect chemical exposure. For example, regulations made at a community level can minimize the exposure of members of the community to secondhand smoke in public places.

On a national level, many organizations are concerned with protecting and improving human health. The Department of Health and Human Services is the U.S. government's principal agency for protecting the health of all Americans. Many different divisions operate within the Department of Health and Human Services. The National Institutes of Health (NIH) is the world's premier medical research organization. Among its many institutes and centers is the National Institute of Environmental Health Sciences (NIEHS), whose mission is to reduce the burden of human illness and dysfunction from environmental causes by understanding how environmental factors, individual susceptibility, and age interrelate. The NIEHS achieves its mission through multidisciplinary biomedical research programs, prevention and intervention efforts, and communication strategies that encompass training, education, technology transfer, and community outreach.

The mission of the Agency for Toxic Substances and Disease Registry (ATSDR) is to prevent adverse effects on human health and diminished quality of life associated with exposure to hazardous substances from waste sites, unplanned releases, and other sources of pollution present in the environment. The ATSDR is directed by congressional mandate to perform specific functions concerning the effect on public health of hazardous substances in the environment. These functions include public health assessments of waste sites, health consultation concerning specific hazardous substances, health surveillance and registries, response to emergency releases of hazardous substances, applied research in support of public health assessments, information development and dissemination, and education and training concerning hazardous substances.

The Food and Drug Administration (FDA) ensures that the food we eat is safe and wholesome, the cosmetics we use don't hurt us, the medicines and medical devices we use are safe and effective, and radiation-emitting products such as microwave ovens won't harm us. Feed and drugs for pets and farm animals also come under FDA scrutiny. The FDA also sees that all of these products are labeled truthfully with the information that people need to use them properly. First and foremost, the FDA is a public health agency, charged with protecting American consumers by enforcing the Federal Food, Drug, and Cosmetic Act and several related public health laws. Investigators and inspectors visit more than 15,000 facilities a year, checking that products are made correctly and labeled truthfully. On average, 3,000 products a year are determined to be unfit for consumers and are withdrawn from the marketplace. In addition, about 30,000 import shipments a year are detained at the port of entry because the goods appear to be unsafe.

In addition to divisions of the Department of Health and Human Services, there are other government agencies for the communal protection of health. The mission of the U.S. Environmental Protection Agency (EPA) is to protect human health and to safeguard the natural environment—air, water, and land—upon which life depends. The EPA's purpose is to ensure that

Part of the U.S. Department of Labor is the Occupational Safety and Health Administration (OSHA). The mission of OSHA is to save lives, prevent injuries, and protect the health of America's workers. To accomplish this, federal and state governments work in partnership with the more than 100 million working men and women and their employers to comply with the Occupational Safety and Health Act of 1970. OSHA currently regulates exposure to approximately 400 workplace substances that are capable of causing harm. Together with the National Institute for Occupational Safety and Health (NIOSH), which is part of the Centers for Disease Control and Prevention (CDC), OSHA provides guidelines about chemicals, including chemical and physical properties, health effects, exposure limits, and recommendations for medical monitoring. These guidelines summarize pertinent information about chemicals for workers and employers as well as for physicians, industrial hygienists, and other occupational safety and health professionals who may need such information to conduct effective occupational safety and health programs.

The U.S. Department of Agriculture (USDA) has agricultural toxicology regulatory authority, and the Food and Nutrition Service (FNS) participates with the CDC on food safety issues.

Notes About Lesson 6

In Lesson 6, students analyze a fictional situation in which members of a class are exposed to a chemical that makes them sick. While they investigate several scenarios in which individual behavior increased the risk of chemical exposure, students recognize that the actual cause of the sickness in the scenario is carbon monoxide poisoning caused by a faulty exhaust system in a school bus. Because the maintenance of the bus is a school district responsibility, and not an individual one, the exposure of students to carbon monoxide is not one over which the exposed students had control. Students see that there are various regulations, agencies, and organizations in place to protect them as citizens from chemical exposure over which they have little control. It is important, however, for students to recognize that they have the right, as citizens of their school, community, nation, and the world, to seek direct input into how to reduce the extent of chemical exposure on a communal level.

As the Evaluate lesson for the curriculum supplement, Lesson 6 offers students the opportunity to express their understanding of the concepts in the supplement in a new context. As students share and compare their ideas with those of others, they can refine and revise them. As you listen to them reasoning out loud, you can assess their individual understanding of human health and the environment.

This lesson is not the only opportunity you have had to assess your students' progress. As noted in each of the previous lessons, assessments have gone hand in hand with instruction throughout the supplement. Whenever individual students expressed themselves by talking, writing, or performing tasks, you have had an opportunity to assess their thinking and thus their learning. The assessment tasks are embedded within the lessons and offer you the opportunity to

The approach to assessment in this supplement is congruent with the following recommendations in the National Science Education Standards.1

In Advance

Web-Based Activities
Activity Number Web Version

Activity 1


Activity 2


Activity Number Master Number Number of Copies

Activity 1

Master 6.1, Heads or Tails?
Master 6.2, Choice Cards
Master 6.3, Fact Sheets on Chemicals

1 for each student (optional)
1 Choice Card for each student (optional)
all pages in the set, at least 5 sets (optional)

Activity 2



Activity 1 Activity 2

For the class:

  • Web site address
  • computers with Internet access
  • 5 sets of fact sheets, copied from Master 6.3, Fact Sheets on Chemicals (optional)
  • 1 red marker (optional)

For each student: (if using Print version)

  • 1 coin
  • 1 copy of Master 6.1, Heads or Tails?
  • 1 Choice Card, copied from Master 6.2, Choice Cards

For each student:

  • 1 copy of completed Heads or Tails? sheet, Master 6.1, from Activity 1 (optional)


Activity 1

Decide whether you will use the Web site or print version of this activity. If you choose to use the Web version, which is preferred, arrange for students to have access to computers.

If you use the print version, gather the materials needed to conduct the activity. Duplicate Master 6.1, Heads or Tails?, 1 for each student. Copy Master 6.2, Choice Cards, and cut apart the cards, making enough for each student to have one card.

Make at least 5 sets of the 6 fact sheets in Master 6.3, Fact Sheets on Chemicals. Fold each fact sheet in half. Label the outside of each sheet with the location from the scenario. Place the sets of fact sheets on a desk in the front of the room.

Activity 2

If you used the print version of Activity 1, students need their completed copy of Master 6.1, Heads or Tails?



The following procedures describe how to conduct the Web version of this activity. Instructions for the print version follow.

National Science Education Standards icon Content Standard A: Students should develop abilities necessary to do scientific inquiry.

1. Gather students in the computer lab and direct them to work with a partner for this Web site activity.

Web activity iconThis activity can be completed using the segment titled The Field Trip on the Web site. Direct students to open the main page of the Web site in their browser (see instructions for using the Web site), click on Web Portion of Student Activities, and then click on Lesson 6—Environmental Hazards.

2. Instruct students to work through the problem posed on the Web site using the available resources, records, and data.

assessment iconCirculate around the room, listening to students as they solve the problem presented on the Web site. Listen to see if students are using the language of toxicology: chemical, dose, response, individual susceptibility, and route of exposure.

3. Once all teams have reached a conclusion about the cause of the illness on the field trip, conduct a class discussion during which teams present their conclusions and their supporting evidence.

Because most students should reach the same conclusion (that a faulty exhaust system in the old yellow bus created carbon monoxide in high enough concentrations to poison some of the students), encourage teams to share one piece of evidence they used to come to their conclusion. Then, let other teams add to the picture of carbon monoxide poisoning, or share evidence for why another chemical exposure probably did not contribute to the illness of the students. In this way, all students have an opportunity to share new ideas.

4. To complete the discussion of the field trip, go to Activity 2.

Print Version
If you do not have access to computers to conduct the Web version of this activity, use the following print version of Activity 1.

1. Tell students that today they are going to participate in a re-creation of a field trip to a natural history museum. To let them know what the field trip was like, read to them the journal entry from one of the participants on the field trip.

Today, we went with our whole class to the Museum of Natural History. It was a cool trip! So much happened that I want to remember, so I am going to write it all down here. First, we all loaded up in the new blue passenger van—you know, the one that the school just bought. It was awesome. The seats are like airline seats and they even have seat belts. We didn’t have to squish three into a seat like we do in the old bus. My friends and I rushed to get the back of the van—it’s better there because we can have the most fun. We had to stop at the gas station to fuel up the van, so we stuck our heads out of the windows in the back and talked to the driver as he filled the tank. I guess we distracted him, because he overflowed the tank and some gas spilled on the ground. Oops! Gasoline sure stinks! Finally, we got back on the road. When we got to the museum, we got a special tour by a paleontologist. She showed us the lab where fossil exhibits are prepared. We stood outside the window and watched the scientists build a model of a dinosaur out of fiber glass and plywood. All the people in the lab wore respirators because I guess there are lots of chemicals in use in there—at least there was a sign on the door that said, “Caution! Chemicals in Use. Authorized Personnel Only.” Then, without even reading the sign, a couple of kids from the class opened the door and went into the lab! Our guide seemed shocked. She pounded on the glass to get a scientist’s attention. A scientist saw the students and hurried them back to the door. I think they got yelled at, but it was hard to tell what the scientist was saying through the respirator. Boy, did they get in trouble from the teacher!

When it was lunch time, we got to eat our sack lunches in the picnic area. It was a neat, big atrium with a really tall glass ceiling. A treat from the teachers was that each of us got to drink a soda that they brought in a big cooler. It was really too bad that they didn’t have more root beer or lemon-lime soda because the new kid had to drink a caffeinated soda because that was all that was left—and she really isn’t supposed to drink it because of some problem she has with caffeine. I would have shared mine with her, but I already took a sip from it.

After lunch they planned for us to go into the hands-on activity room. We got to paint plaster models of dinosaurs. What a mess we made! Some kids got paint all over their skin and needed to wash it off at the sink. We got sort of wild by the time we finished the project, and I think our teachers were ready to get us back to school.

When we went outside the museum, we saw the old yellow bus there to pick us up. My friends groaned—no more plush seats and clean windows. I never feel as safe in the old bus because there aren’t seat belts, so I sat in the front of the bus going back to school, squished into a seat with two other people. I sure was glad to get to the school. The funny thing was that we weren’t nearly as noisy going home as we were going to the museum. I guess we were tired. It was a fun day anyway.

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